1. Field of the Invention
The invention relates to “smart labels” or RFID tags, specifically RFID tags with a tamper evident or tamper indicating feature.
2. Description of the Related Art
Prior smart labels in the Automatic Identification Industry do not display evidence of tampering when removed or peeled away from a substrate. Most common paper or film labels with a pressure sensitive adhesive can easily be peeled up from a surface without tearing or damaging the label stock. Therefore, there is a need for a label that is made from a tamper-indicating material that would prevent access to the embedded RFID transponder without noticeable damage to the label stock. This security feature would prevent the RFID transponder from being removed, altered, replaced, or transferred to another label or substrate.
Radio frequency transponders (also known as “RFID tags”) generally include an antenna and integrated memory circuit with read/write capability used to store digital information, such as an electrically erasable programmable read only memory (EEPROM) or similar electronic device. Active RFID tags include their own radio transceiver and power source (battery) and are generally sealed within a molded plastic housing or “button”. Passive RFID tags are energized to transmit and receive data by an electromagnetic field and do not include a radio transceiver or power source. As a result, they are small and inexpensive with limited range, resolution, and data storage capacity. Some common passive RFID tags include the Intermec Intellitag 500 ™ and Texas Instruments' TagIt ™. Passive RFID tags used in the Automatic Identification Industry are typically laminated or inserted into a paper or synthetic label stock backed with pressure sensitive adhesive for applying the printed label to a carton, automobile, pallet, airline baggage, parcel, or other article to be tracked. These labels are commonly referred to as “smart labels”.